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New Caledonian Crow
| image_width = 240px | regnum = Animalia | phylum = Chordata | classis = Aves | ordo = Passeriformes | familia = Corvidae | genus = Corvus | species = C. moneduloides | binomial = Corvus moneduloides | binomial_authority = Lesson, 1830 | range_map = Corvus_moneduloides_map.jpg }} The New Caledonian Crow (Corvus moneduloides) is a tool-using species of crow endemic to New Caledonia. These crows are able to make hooks, an ability that not even our closest relative, the chimpanzee, has mastered. This species is not just famous for its tool-making abilities. These crows have also solved a number of sophisticated cognitive tests which suggest that this species is particularly intelligent Taylor et al. 2010, Taylor et al. 2012). Due to these findings this species has become a model species for scientists trying to understand the impact of tool use and manufacture on the evolution of intelligence. Description The New Caledonian Crow (Corvus moneduloides) is a moderately sized crow (40 cm in length) similar in size to the House Crow but less slender-looking. The bird has an all-black appearance with a rich gloss to its feathers of purple, dark blue and some green in good light. The beak, feet and legs are all black. The beak is of moderate size but is unusual in that the tip of the lower is angled up making it somewhat chisel-like in profile. It has been suggested that the beak evolved this morphology due to the selective pressures created by the need to hold a tool straight. The voice is described as a soft "waa-waa" or "wak-wak", and sometimes as a hoarse "qua-qua" or "waaaark". Across New Caledonia the birds is often referred to as a 'qua-qua' due to its distinctive call. Distribution and habitat The bird is endemic to the islands of New Caledonia in the Pacific, living in primary forest. It inhabits only the main island, Grande Terre, and one of the Loyalty Islands, Maré Island. Animal cognition Animal attention Animal intelligence Tool use and manufacture This species uses stick tools in the wild by finding small twigs and probing them into hole in logs to extract insects and larvae. New Caledonian crows are also able to manufacture tools by breaking twigs off bushes and trimming them to produce functional stick tools. Tool manufacture is rare in comparison to simple tool use and indicates a higher level of cognitive function. The crows can also make leaf tools by tearing rectangular strips off the edges of Pandanus spp. leaves. The creation of such leaf tools allows these crows to exploit naturally occurring hooks – the barbs running along the edges of these leaves can be used as hooks if the tool is held such that the barbs point towards the crows’ head. Other naturally occurring hooks are also incorporated within tools, such as the thorns that grow on vine species in New Caledonia. These crows create hooks by crafting both wood and ferns into hooks. This is done by trimming the junctions between two branches or fern stolons into a tick shape (i.e. one junction has a long piece of wood/stolon attached, one junction has a small piece of wood /stolon attached) and then removing material from this junction to create a functioning hook. This imposition of three-dimensional form onto a natural material resembles carving. The only other species to exhibit hook tool manufacture is humans. The New Caledonian Crow is the only non-primate species for which there is evidence of cumulative cultural evolution in tool manufacture. That is, this species appear to have invented new tools by modifying existing ones, then passing these innovations to other individuals in the cultural group. Gavin R. Hunt and colleagues at the University of Auckland studied tools the crows make out of pandanus (or screw pine) leaves: }} Observations of the distribution of 5,500 leaf counterparts or stencils left behind by the cutting process suggest that the narrow and the stepped tools are more advanced versions of the wide tool type. "The geographical distribution of each tool type on the island suggests a unique origin, rather than multiple independent inventions". This implies that the inventions, which involve a delicate change in the manufacturing process, were being passed from one individual to another. The New Caledonian Crow also spontaneously makes tools from materials it does not encounter in the wild, the only non-human species known to do so. In 2002, researcher Alex Kacelnik and colleagues at the University of Oxford observed of a couple of New Caledonian Crows called Betty and Abel: }} Subsequently, this ability was tested through a series of systematic experiments. Out of ten successful retrievals, Betty bent the wire into a hook nine times. Abel retrieved the food once, without bending the wire. The process would usually start with Betty trying to get the food bucket with the straight wire, but then she would make a hook from it bending it in different ways, usually by snagging one end of the wire under something, and then using the bent hook to pick up the tray. Clearly, Betty's creation of hooks cannot be attributed to the shaping or reinforcement of trial-and-error behavior. In 2004, Gavin Hunt observed the crows in the wild also making hooks, but the adaptation to the new material of the wire was clearly novel, and also purposeful. This type of intentional tool-making, even if it is generalizing a prior experience to a completely new context, is rare in the animal world. Chimpanzees have great difficulty in similar innovative tasks. The use of direct human activity has been recorded as well. This involves placing nuts in front of a vehicle on a heavy trafficked street, waiting for a car to crush it open and then waiting at pedestrian lights with other pedestrians to retrieve the crushed nut safely.EduTube Educational Videos video does not play August 27, 2013 Meta-tool use Recent experiments show that New Caledonian Crows are able to use one tool to affect another to achieve a task, at a level rivalling the best performances seen in primates. One such experiment, conducted by the Auckland team, involved putting food in a box out of the crows' reach. They were given a stick too short to reach the food, but they could use this to retrieve a longer stick from another box. The longer stick was then used to retrieve the food. This complex behaviour involved realising that a tool could be used on non-food objects, and suppressing the urge to go directly for the food. It was solved by six of seven birds on the first attempt, and had previously only been observed in primates. The crows also use tools to investigate potentially dangerous objects. Mirror use Some crows that were captured from the wild showed the ability to use mirrors to find objects they could not see with a direct line of sight. The birds tested did not immediately recognise themselves in the mirror, which may be due to their never having seen a mirror before. Individual crows showed different levels of ability. Animal language and communication Animal learning Animal memory Animal sensory perception Animal auditory perception Animal haptic perception [[Animal olfactory perception Animal taste perception Animal visual perception Animal colour perception Animal depth perception Animal form and shape perception Animal nonsensory perception Animal numerosity perception Animal pain perception Animal perception of movement and action Animal pitch perception Animal rhythm perception Animal time perception Animal problem solving Animal reasoning Ethology Animal innate behavior Animal defensive behavior Animal division of labour Animal drinking behavior Animal escape behaviour Animal feeding behaviour It eats a very wide range of food, including many types of insects and other invertebrates (some caught in flight with some agility, including night-flying insects which it catches at dusk), eggs and nestlings, small mammals, snails (which it drops from a height onto hard stones), and various nuts and seeds. It is known for using plant material to create stick and leaf tools. These tools can have naturally occurring barb incorporated into them, and can be actually fashioned into hooks. These tools are use for extracting large grubs from inside logs and branches, which have been shown to be an integral part of the crows' diet. This bird appears to fill the ecological niche of the woodpeckers and the Woodpecker Finch of the Galapagos, since the latter and New Caledonia lack woodpeckers. Unlike the Woodpecker Finch, however, it does not simply stab a grub and lever it slowly out of its log using a small twig but pokes the twig at the grub to agitate it into biting the twig. It shows great ingenuity in the search for food. Animal exploratory behavior Animal grooming behavior Animal hoarding behavior Animal instinctive behavior Animal licking behavior Animal nocturnal behavior Animal motivation Animal predatory behavior Animal scent marking Migratory behavior (animal) Animal open field behavior Alarm responses Animal breeding Animal foraging behavior Animal homing Animal locomotion Animal navigation Migratory behaviour (animal) Animal physiological psychology Animal biological rhythms Animal circadian rythms Animal colouration Animal drinking behavior Animal emotionality Animal feeding behavior Animal sexual behavior Animal courtship behavior Animal courtship displays Animal sex differences Animal sexual receptivity Animal mating behavior Animal mate selection Animal parental behavior Animal maternal behavior Animal maternal deprivation Animal paternal behaviour Animal play Nestbuilding Its nest is built high in a tree with usually 2-3 eggs laid from September to November. Animal social behavior Animal defensive behavior Animal distress calls Animal dominance Animal communication Animal vocalizations Species recognition Territorality Animals and man Animal assisted therapy Animal breeding Animal captivity Animal domestication Animal human interaction Animal rearing Pets Interspecies interaction References External links * Oxford University crow research web site, including photos and movies * Auckland University crow web page, an introduction to their field-based research on crows' tool manufacture and use, including video footage of meta-tool use * From National Geographic: A video of the New Caledonian Crow making a hook out of wire (August 8, 2002) * Tool use in crows is a combination of natural ability and schooling by other crows – LiveScience.com (October 31, 2006) * BBC news website item about the New Caledonian Crow, includes video footage of tool use (August 16, 2007) * Crow bends wire on purpose to lift bucket from glass tube (Nat'l Geo link no longer contains video).—YouTube Category:Corvus Crow, New Caledonian Crow, New Caledonian Category:Tool-using species Category:Animals described in 1830